4 - Alpha Omega Alpha

David P. Hill
Editorial
Marat and Harvey, revolutionaries
Edward D. Harris, Jr., MD
Revolution is defined in several ways. One is the forcible
overthrow of a government or social order in favor
of a new system. This type of revolution invariably
occurs over a short period of time. “Marat’s Terror” by Jesse
Woodard (pp. 17–24) describes the troubled but powerful life
of physician/ polemicist Jean-Paul Marat and his role in the
French Revolution. His fiery doctrines were quenched suddenly
when Charlotte Corday stabbed him while he bathed.
Revolutions in medicine and the medical sciences
are less radical and follow a second definition: a dramatic
and wide- reaching change in the way something
works or is organized and in people’s ideas
about it, a transition from one paradigm to another.
Today’s physicians and scientists are familiar with
this type of revolution. We have experienced the
discovery of penicillin, streptomycin, and cortisone;
the development of vaccines against poliomyelitis
and other infectious scourges; the definition of the
structure of DNA, the translation of the genetic
code, and the establishment of methods to synthesize
DNA; the initiation and growth of transplant
surgery; the technical advances informing CT, MRI,
microarrays, and stem cell biology; and the slower
but no less important revolutions in public health.
We relish the exploration of the unknown.
Why did it take more than 1500 years, from
the first to the seventeenth century, for empiric
observations to enable understanding of the circulation?
Galen, in the first century AD, adopted the
Hippocratic theory of the four humours: blood, phlegm, and
yellow and black bile, and the importance of having balance
among them to ensure good health. Although reported to be
conceited, cruel, and vindictive, he cannot be blamed for the
blind allegiance to his teachings that persisted for centuries.
Those who followed Galen failed to use the tools they had—
eyes, brain, and hands—for at least two reasons: first, human
dissection was prohibited, and second, it was philosophers
and the clergy who for many centuries determined the truths
of life for the people. Most significant among those who led
thought was Aristotle. Bertrand Russell writes that ”it was two
thousand years before the world produced any philosopher
who could be regarded as approximately his equal.” 1 It was
Aristotle who gave science to mankind. He observed, and
deduced logical conclusions. Consider his realization that
no drop of water has been added to nor taken from the earth
and its atmosphere since creation: “This is a cyclic world, says
our philosopher: the sun forever evaporates the sea, dries up
rivers and springs, and transforms at last the boundless ocean
into the barest rock; while conversely the uplifted moisture,
gathered into clouds, falls and renews the rivers and the seas,”
writes Will Durant. 2 Aristotle observed that life was growing
steadily in complexity and power, with increasingly specialized
function. Indeed, he was on the verge of deducing the theory
of evolution. Why then was Aristotle not the one to define the
physiology of the circulation, that the heart (not the brain)
pumped blood through arteries, and that blood flowed back
to the pump through thinner vessels, the veins? He certainly
had each of the tools—eyes, a brain, and hands—needed to
do this.
William Harvey based his
theory of the circulation of the
blood on a series of simple experiments
in which he studied
venous blood flow using
a tourniquet and digital compression.
His famous book,
“Ecercitatio anatomica de motu
cordis,” published in 1628, illustrates
these experiments and
elucidates the observations he
made and deductive reasoning
he used to arrive at this theory.
Traditionalists following in the
footsteps of Galen attempted
to reject Harvey’s conclusions,
but uniformly failed to find
weaknesses in either his experiments
or deductions because
to deny a single part of
Harvey’s theory would be to reject the whole, and this was
impossible. Nevertheless, many tried!
The revolution sparked by Harvey’s new paradigm brought
much new knowledge from diverse sources. For example,
Antoine van Leeuwenhoek built an instrument, the microscope,
that would be a revolution in itself. Leeuwenhoek’s
microscope revealed the presence of red blood cells and, more
importantly, the hair-thin anastomoses between the blood
vessels that he named “capillaries,” a discovery that linked the
veins and arteries to complete the elements of the circulation
that Harvey had outlined.
Scientific revolutions continue to evolve in both intensity
and sophistication, combining the resources of eyes, brains,
and hands to bring biological science to the heights it has
reached today, with more to be ascended tomorrow.
Courtesy of the National Library of Medicine
References
1. Russell B. History of Western Philosophy. London: George
Allen & Unwin; 1974: 173.
2. Durant W. The story of philosophy. New York: Simon and
Schuster; 1953: 53.
The Pharos/Spring 2009 1